<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<div id="app">
    <h2 :style="{fontSize: '50px'}">{{message}}</h2>
    <!--50px必须加上单引号，否则会被当作字符串解析-->
    <h2 :style="{fontSize: finalSize + 'px', color: finalColor}">{{message}}</h2>
    <!--finalSize当成一个变量使用-->
    <h2 :style="getStyles()">{{message}}</h2>
</div>

<script src="../../js/vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
            message: '你好啊',
            finalSize: 100,
            finalColor: 'red'
        },
        methods: {
            getStyles: function () {
                return {fontSize: this.finalSize + 'px', color: this.finalColor}
            }
        }
    })
</script>

</body>
</html>